BT Tech offered one and may still. (They sell the strut tower brace, under-belly pan, and cross brace for under the car.) I had one of their spoilers, which is a very nice looking spoiler on the car, it is suttle and sits right at the glass edge. The problem I had is it kept lifting from the car, as it was attatched with double stick tape. I ended up removing mine due to that. My experience could be unique though. Give Brian at BT Tech a call.
Elreq, Can you reply back on what you heard from BT-Tech? I'm curious as to whether they will still be available for my next Prius. Dan